Direct Objects

One problem with the traditional definition of direct object as "receiver of the action" is that with some verbs it's hard to envision how the direct object could be receiving anything; for example:

With a stative verb:

or even with verbs that aren't stative:

Heloise refused the invitation.

You can identify a direct object, using both grammatical knowledge and an understanding of conditions that are likely to hold true in the real world, because, in the vast majority of cases, a direct object will be a NP (or pronoun) that is not coreferential with (the same thing as) the subject.

Consider, for example: Heloise ate the donut.

Whatever else we know about Heloise, chances are shešs not a donut, so the NPs Heloise and a donut are not coreferential. (We can leave aside J.F.K.'s I ch bin ein Berliner. "I am a Berliner." (a kind of jelly donut) because he intended the second NP as a subjective complement (just Berliner ), his audience understood his intentions, and the sentence was in German anyway).

The only cases where the subject and the direct object ARE correferential are pretty easy to figure out, since the direct object is a reflexive pronoun marked with -self (singular) or -selves (plural).

Alfred washed himself.
He shaved himself.
The children behaved themselves.
She carried herself with dignity.

For example:

We know the reflexive pronoun direct objects have to be coreferential with the subject, because the reflexive pronouns have to agree in number and gender with the subject. That is why the following sentences are ungrammatical:

*Alfred washed themselves.

(The subject is third person singular but the pronoun is third person plural.)

*He shaved herself.

(The subject is masculine but the pronoun is feminine.)

*The children behaved itself.

(The subject is plural and refers to human beings, but the pronoun is third person singular neuter).